Long-term cognitive and neurovascular changes after carotid endarterectomy

BACKGROUND

Carotid endarterectomy (CEA) has been associated with both cognitive decline and improvement, but the underlying neurovascular mechanisms are unclear. The aim of this study was to investigate the relationship between neurovascular indices and cognitive changes after CEA.

METHODS

We studied 55 patients with severe (≥70%) symptomatic or asymptomatic carotid stenosis before and six months after CEA. A wide array of neuropsychological tests was arranged in eight cognitive domains and cognitive functions specific to hemisphere ipsilateral to operation. Differences in cognitive performance between patients and 38 matching healthy controls were studied with linear mixed models. Neurovascular functioning and microembolic signals were assessed with transcranial Doppler ultrasound of the middle cerebral artery. Associations between neurovascular indices and cognitive change were assessed with linear regression analyses.

RESULTS

On group level, the CEA patients improved more than controls in working memory, whereas no cognitive deterioration was detected. Also on individual level, improvement was most frequently observed in working memory. Worse preoperative cerebrovascular reactivity was related with improvement in cognitive functions of the ipsilateral hemisphere. Low preoperative pulsatility index was associated with improvement in executive functioning and ipsilateral cognitive functions. Poorer preoperative blood flow velocity associated with improvement in complex attention. Microembolic signals were rare.

CONCLUSION

The present findings suggest that CEA may have beneficial long-term effects on cognition. These effects may specifically involve patients with impaired preoperative circulatory adaptive mechanisms.

Adult vasovagal syncope with abdominal pain diagnosed by head-up tilt combined with transcranial doppler: a preliminary study

BACKGROUND

Syncope is a common condition that increases the risk of injury and reduces the quality of life. Abdominal pain as a precursor to vasovagal syncope (VVS) in adults is rarely reported and is often misdiagnosed.​.

METHODS

We present three adult patients with VVS and presyncopal abdominal pain diagnosed by synchronous multimodal detection (transcranial Doppler [TCD] with head-up tilt [HUT]) and discuss the relevant literature.

RESULTS

Case 1: A 52-year-old man presented with recurrent decreased consciousness preceded by six months of abdominal pain. Physical examinations were unremarkable. Dynamic electrocardiography, echocardiography, head and neck computed tomography angiography, magnetic resonance imaging (MRI), and video electroencephalogram showed no abnormalities. Case 2: A 57-year-old woman presented with recurrent syncope for 30 + years, accompanied by abdominal pain. Physical examination, electroencephalography, and MRI showed no abnormalities. Echocardiography showed large right-to-left shunts. Case 3: A 30-year-old woman presented with recurrent syncope for 10 + years, with abdominal pain as a precursor. Physical examination, laboratory analysis, head computed tomography, electrocardiography, and echocardiography showed no abnormalities. Syncope secondary to abdominal pain was reproduced during HUT. Further, HUT revealed vasovagal syncope, and synchronous TCD showed decreased cerebral blood flow; the final diagnosis was VVS in all cases.

CONCLUSIONS

Abdominal pain may be a precursor of VVS in adults, and our findings enrich the clinical phenotypic spectrum of VVS. Prompt recognition of syncopal precursors is important to prevent incidents and assist in treatment decision-making. Abdominal pain in VVS may be a sign of sympathetic overdrive. Synchronous multimodal detection can help in diagnosing VVS and understanding hemodynamic mechanisms.

Point-of-care brain ultrasound and transcranial doppler or color-coded doppler in critically ill neonates and children

Point-of-care brain ultrasound and transcranial doppler or color-coded doppler is being increasingly used as an essential diagnostic and monitoring tool at the bedside of critically ill neonates and children. Brain ultrasound has already established as a cornerstone of daily practice in the management of the critically ill newborn for diagnosis and follow-up of the most common brain diseases, considering the easiness to insonate the brain through transfontanellar window. In critically ill children, doppler based techniques are used to assess cerebral hemodynamics in acute brain injury and recommended for screening patients suffering from sickle cell disease at risk for stroke. However, more evidence is needed regarding the accuracy of doppler based techniques for non-invasive estimation of cerebral perfusion pressure and intracranial pressure, as well as regarding the accuracy of brain ultrasound for diagnosis and monitoring of acute brain parenchyma alterations in children. This review is aimed at providing a comprehensive overview for clinicians of the technical, anatomical, and physiological basics for brain ultrasonography and transcranial doppler or color-coded doppler, and of the current status and future perspectives of their clinical applications in critically ill neonates and children.

CONCLUSION

In critically ill neonates, brain ultrasound for diagnosis and follow-up of the most common cerebral pathologies of the neonatal period may be considered the standard of care. Data are needed about the possible role of doppler techniques for the assessment of cerebral perfusion and vasoreactivity of the critically ill neonate with open fontanelles. In pediatric critical care, doppler based techniques should be routinely adopted to assess and monitor cerebral hemodynamics. New technologies and more evidence are needed to improve the accuracy of brain ultrasound for the assessment of brain parenchyma of critically ill children with fibrous fontanelles.

WHAT IS KNOWN

• In critically ill neonates, brain ultrasound for early diagnosis and follow-up of the most common cerebral and neurovascular pathologies of the neonatal period is a cornerstone of daily practice. In critically ill children, doppler-based techniques are more routinely used to assess cerebral hemodynamics and autoregulation after acute brain injury and to screen patients at risk for vasospasm or stroke (e.g., sickle cell diseases, right-to-left shunts).

WHAT IS NEW

• In critically ill neonates, research is currently focusing on the use of novel high frequency probes, even higher than 10 MHz, especially for extremely preterm babies. Furthermore, data are needed about the role of doppler based techniques for the assessment of cerebral perfusion and vasoreactivity of the critically ill neonate with open fontanelles, also integrated with a non-invasive assessment of brain oxygenation. In pediatric critical care, new technologies should be developed to improve the accuracy of brain ultrasound for the assessment of brain parenchyma of critically ill children with fibrous fontanelles. Furthermore, large multicenter studies are needed to clarify role and accuracy of doppler-based techniques to assess cerebral perfusion pressure and its changes after treatment interventions.

Effect of continuous 2 MHz transcranial ultrasound as an adjunct to tenecteplase thrombolysis in acute anterior circulation ischemic stroke patients: an open labeled non-randomized clinical trial

The treatment of acute ischemic stroke has improved in last few decades. While meta-analyses of several trials have established the safety and efficacy of Intravenous (IV) Tenecteplase thrombolysis, concomitant continuous transcranial doppler (TCD) ultrasound administration has not been assessed in any clinical trial. The aim of this study was to determine the effects of continuous 2 MHz TCD ultrasound during IV Tenecteplase thrombolysis for Middle cerebral artery (MCA) stroke. A total of 19 patients were included, 13 received TCD ultrasound and 6 sham TCD with IV Tenecteplase. TCD spectrum and difference in Pre and post TCD parameters were measured. Asymptomatic hemorrhagic transformation of infarct was seen in two patients. There was no mortality or clinical worsening in the sonothrombolysis group as against sham sonothrombolysis group. Median of peak systolic velocity was increased in both the sonothrombolysis (P = 0.0002) and sham sonothrombolysis group (P-value = 0.001). The difference in change in mean flow velocity between two groups, sonothrombolysis (11 cm/sec) and sham sonothrombolysis (3.5 cm/sec) were also significantly different (P = 0.014). This pilot work has established safety of continuous 30 min TCD application along with IV Tenecteplase thrombolysis and it concludes that concomitant 2 MHz TCD ultrasound administration significantly increased the MCA blood flow compared to chemothrombolysis alone.CTRI Registered Number: CTRI/2021/02/031418.

Is medical management useful in Moyamoya disease?

Moyamoya disease (MMD), characterized by progressive internal carotid artery stenosis and collateral vessel formation, prompts cerebral perfusion complications and is stratified into idiopathic and Moyamoya syndrome subtypes. A multifaceted approach toward MMD management addresses cerebral infarctions through revascularization surgery and adjunctive medical therapy, while also navigating risks such as intracranial hemorrhage and cerebral infarction resulting from arterial stenosis and fragile collateral vessels. Addressing antithrombotic management reveals a potential role for treatments like antiplatelet agents and anticoagulants, despite the ambiguous contribution of thrombosis to MMD-related infarctions and the critical balance between preventing ischemic events and averting hemorrhagic complications. Transcranial doppler has proven useful in thromboembolic detection, despite persisting challenges concerning the efficacy and safety of antithrombotic treatments. Furthermore, antihypertensive interventions aim to manage blood pressure meticulously, especially during intracerebral hemorrhage, with recommendations and protocols varying based on the patient's hypertension status. Additionally, lipid-lowering therapeutic strategies, particularly employing statins, are appraised for their possible beneficial role in MMD management, even as comprehensive data from disease-specific clinical trials remains elusive. Comprehensive guidelines and protocols to navigate the multifaceted therapeutic avenues for MMD, while maintaining a delicate balance between efficacy and safety, warrant further meticulous research and development. This protocol manuscript seeks to elucidate the various aspects and challenges imbued in managing and navigating through the complex landscape of MMD treatment.

Prediction of neurocritical care intensity through automated infrared pupillometry and transcranial doppler in blunt traumatic brain injury: the NOPE study

PURPOSE

This pilot study aimed to determine the capacity of automated infrared pupillometry (AIP) alone and in combination with transcranial doppler (TCD) on admission to rule out need for intense neuroAQ2 critical care (INCC) in severe traumatic brain injury (TBI).

METHODS

In this observational pilot study clinicians performed AIP and TCD measurements on admission in blunt TBI patients with a Glasgow Coma Score (GCS) < 9 and/or motor score < 6. A Neurological Pupil index (NPi) < 3, Pulsatility Index (PI) > 1,4 or diastolic blood flow velocity (dV) of < 20 cm/s were used to rule out the need for INCC (exceeding the tier 0 Seattle Consensus Conference). The primary outcome was the negative likelihood ratio (nLR) of NPi < 3 alone or in combination with TCD to detect need for INCC.

RESULTS

A total of 69 TBI patients were included from May 2019 to September 2020. Of those, 52/69 (75%) median age was 45 [28-67], median prehospital GCS of 7 [5-8], median Injury Severity Scale of 13.0 [6.5-25.5], median Marshall Score of 4 [3-5], the median Glasgow Outcome Scale at discharge was 3 [1-5]. NPi < 3 was an independent predictor of INCC. NPi demonstrated a nLR of 0,6 (95%CI 0.4-0.9; AUROC, 0.65, 95% CI 0.51-0.79), a combination of NPi and TCD showed a nLR of 0.6 (95% CI 0.4-1.0; AUROC 0.67 95% CI 0.52-0.83) to predict INCC.

CONCLUSION

This pilot study suggests a possible useful contribution of NPi to determine the need for INCC in severe blunt TBI patients on admission.

Standing middle cerebral artery velocity predicts cognitive function and gait speed in older adults with cognitive impairment, and is impacted by sex differences

Upright posture challenges the cerebrovascular system, leading to changes in middle cerebral artery velocity (MCAv) dynamics which are less evident at supine rest. Chronic alterations in MCAv have been linked to hypoperfusion states and the effect that this may have on cognition remains unclear. This study aimed to determine if MCAv and oscillatory metrics of MCAv (ex. pulsatility index, PI) during upright posture are i) associated with cognitive function and gait speed (GS) to a greater extent than during supine rest, and ii) are different between sexes. Beat-by-beat MCAv (transcranial Doppler ultrasound) and mean arterial pressure (MAP, plethysmography) were averaged for 30-seconds during supine-rest through a transition to standing for 53 participants (73±6yrs, 17 females). While controlling for age, multiple linear regressions predicting MoCA scores and GS from age, supine MCAv metrics, and standing MCAv metrics, were completed. Simple linear regressions predicting Montreal Cognitive Assessment (MoCA) score and GS from MCAv metrics were performed separately for females and males. Significance was set to p<0.05. Lower standing diastolic MCAv was a significant (p = 0.017) predictor of lower MoCA scores in participants with mild cognitive impairment, and this relationship only remained significant for males. Lower standing PI was associated with slower GS (p = 0.027, r=-0.306) in both sexes. Our results indicate a relationship between blunted MCAv and altered oscillatory flow profiles during standing, with lower MoCA scores and GS. These relationships were not observed in the supine position, indicating a unique relationship between standing measures of MCAv with cognitive and physical functions.

Neuromonitoring During ECMO Support in Children

Extracorporeal membrane oxygenation is a potentially lifesaving intervention for children with severe cardiac or respiratory failure. It is used with increasing frequency and in increasingly more complex and severe diseases. Neurological injuries are important causes of morbidity and mortality in children treated with extracorporeal membrane oxygenation and include ischemic stroke, intracranial hemorrhage, hypoxic-ischemic injury, and seizures. In this review, we discuss the epidemiology and pathophysiology of neurological injury in patients supported with extracorporeal membrane oxygenation, and we review the current state of knowledge for available modalities of monitoring neurological function in these children. These include structural imaging with computed tomography and ultrasound, cerebral blood flow monitoring with near-infrared spectroscopy and transcranial Doppler ultrasound, and physiological monitoring with electroencephalography and plasma biomarkers. We highlight areas of need and emerging advances that will improve our understanding of neurological injury related to extracorporeal membrane oxygenation and help to reduce the burden of neurological sequelae in these children.

Transcranial doppler in the non-invasive estimation of intracranial pressure in traumatic brain injury compared to other non-invasive methods in lower-middle income countries: Systematic review and meta-analysis

BACKGROUND

The prediction of raised Intracranial Pressure (ICP) with accuracy in Traumatic Brain Injury (TBI) patients is a clinically important decision and therapeutic tool. This study aimed to evaluate the existing methods used for non-invasive ICP monitoring in TBI patients in LMICs.

METHODS

Systematic searches of PubMed, Google Scholar, and ScienceDirect were performed from database inception to November 2021. Studies reporting the prediction of raised ICP in TBI patients by non-invasive means in LMICs were included. Pooled estimates of sensitivity, specificity, positive likelihood ratios, and negative likelihood ratios with 95 %CI were calculated for each index test consisting of the fifteen studies, using the MEDDECIDE module 0.0.2 for meta-analysis of diagnostic test accuracy, reliability, and decision studies in JAMOVI 2.2.5.

RESULTS

A total of 1032 studies were identified, of which, 15 included 3316 patients with male predominance (n = 2458, 74.13%). Patients' ages range from 15 to 96 years with 40-80 (n = 1205, 36.34%), the most represented population. The ICP measured by Transcranial Doppler (TCD) had a sensitivity of 92.3%, and a specificity of 70%. The positive predictive value was 66.67%, with a negative predictive value of 93.33%. Furthermore, the positive Likelihood Ratio (+LR) was 3.69; 2<+LR < 5 and the negative Likelihood Ratio (-LR) 0.103; 0.1 < -LR < 0.2. We carried out a "Medical Decision", "Plots", "Fagan Normogram" and the ROC curve to find the perfect discrimination point of all the five tests used for the non-invasive measurement of ICP in the TBI patients in LMICs.

CONCLUSION

The TCD had shown high performance in its sensitivity and specificity, placing it on top of the other four different tests used in LMICs for the management of patients with TBI.

Ultrasound-guided cerebral resuscitation in patients with severe traumatic brain Injury

Traumatic brain injury (TBI) is a worldwide public health concern given its significant morbidity and mortality, years of potential life lost, reduced quality of life and elevated healthcare costs. The primary injury occurs at the moment of impact, but secondary injuries might develop as a result of brain hemodynamic abnormalities, hypoxia, and hypotension. The cerebral edema and hemorrhage of the injured tissues causes a decrease in cerebral perfusion pressure (CPP), which leads to higher risk of cerebral ischemia, herniation and death. In this setting, our role as physicians is to minimize damage by the optimization of the CPP and therefore to reduce mortality and improve neurological outcomes. Performing a transcranial doppler ultrasound (TCD) allows to estimate cerebral blood flow velocities and identify states of low flow and high resistance. We propose to include TCD as an initial assessment and further monitoring tool for resuscitation guidance in patients with severe TBI. We present an Ultrasound-Guided Cardio-cerebral Resuscitation (UGCeR) protocol in Patients with Severe TBI.

The effects of aneurysmal subarachnoid hemorrhage on cerebral vessel diameter and flow velocity

BACKGROUND

Transcranial Doppler flow velocity is used to monitor for cerebral vasospasm following aneurysmal subarachnoid hemorrhage. Generally, blood flow velocities appear inversely related to the square of vessel diameter representing local fluid dynamics. However, studies of flow velocity-diameter relationships are few, and may identify vessels for which diameter changes are better correlated with Doppler velocity. We therefore studied a large retrospective cohort with concurrent transcranial Doppler velocities and angiographic vessel diameters.

METHODS

This is a single-site, retrospective, cohort study of adult patients with aneurysmal subarachnoid hemorrhage, approved by the UT Southwestern Medical Center Institutional Review Board. Study inclusion required transcranial Doppler measurements within </= 24 hours of vessel imaging. Vessels assessed were: bilateral anterior, middle, posterior cerebral arteries; internal carotid siphons; vertebral arteries; and basilar artery. Flow velocity-diameter relationships were constructed and fitted with a simple inverse power function. A greater influence of local fluid dynamics is suggested as power factors approach two.

RESULTS

98 patients were included. Velocity-diameter relationships are curvilinear, and well fit by a simple inverse power function. Middle cerebral arteries showed the highest power factors (>1.1, R²>0.9). Furthermore, velocity and diameter changed (P<0.033) consistent with the signature time course of cerebral vasospasm.

CONCLUSIONS

These results suggest that middle cerebral artery velocity-diameter relationships are most influenced by local fluid dynamics, which supports these vessels as preferred endpoints in Doppler detection of cerebral vasospasm. Other vessels showed less influence of local fluid dynamics, pointing to greater role of factors outside the local vessel segment in determining flow velocity.

Traumatic Brain Injury: Intraoperative Management and Intensive Care Unit Multimodality Monitoring

Traumatic brain injury is a devastating event associated with substantial morbidity. Pathophysiology involves the initial trauma, subsequent inflammatory response, and secondary insults, which worsen brain injury severity. Management entails cardiopulmonary stabilization and diagnostic imaging with targeted interventions, such as decompressive hemicraniectomy, intracranial monitors or drains, and pharmacological agents to reduce intracranial pressure. Anesthesia and intensive care requires control of multiple physiologic variables and evidence-based practices to reduce secondary brain injury. Advances in biomedical engineering have enhanced assessments of cerebral oxygenation, pressure, metabolism, blood flow, and autoregulation. Many centers employ multimodality neuromonitoring for targeted therapies with the hope to improve recovery.

Changes in Cerebral Hemodynamics During Systemic Pulmonary Shunt and Pulmonary Artery Banding in Infants with Congenital Heart Disease

Palliative surgery is often performed in the treatment of congenital heart disease. Two representative palliative procedures are the systemic pulmonary shunt and pulmonary artery banding. Dramatic changes in cerebral hemodynamics may occur in these operations due to changes in the pulmonary-to-systemic blood flow ratio and systemic oxygenation. However, there seem to be almost no studies evaluating them. Accordingly, we evaluated cerebral perfusion by transcranial Doppler ultrasonography and cerebral oxygenation by near infrared spectroscopy during these procedures. In the post hoc analysis of a previous prospective observational study, cerebral blood flow velocities of the middle cerebral artery measured by transcranial Doppler were compared between the start and end of surgery as were the pulsatility index and resistance index. The cerebral oxygenation values were also compared between the start and end of surgery. Twenty-two infants with systemic pulmonary shunt and 20 infants with pulmonary artery banding were evaluated. There were no significant differences of the flow velocities between the start and end of surgery in either procedure. The pulsatility index significantly increased after pulmonary artery banding, which may compete with the increase in cerebral perfusion due to the increase in systemic blood flow. The cerebral oxygenation decreased in both procedures, possibly due to an increase in body temperature. Arterial oxygen saturation was almost the same before and after both procedures. Contrary to our expectation, the changes in cerebral hemodynamics in the palliative operations were small if the management of physiological indices such as arterial oxygen saturation was properly performed during the procedures.

A novel computational fluid dynamic method and validation for assessing distal cerebrovascular microcirculatory resistance

BACKGROUND AND OBJECTIVE

The non-invasive assessment of microcirculatory resistance could improve the treatment of cerebrovascular stenosis. This study aimed to validate a novel computational strategy for determining the reference value of microcirculatory resistance in patients with cerebrovascular stenosis.

METHODS

We reconstructed a patient-specific 3-dimensional model of the extracranial-intracranial arteries. A computational strategy incorporating patient-specific pressure-wire measurements was developed to estimate the blood flow rate and microcirculatory resistance. Throughout the computational fluid dynamics (CFD) simulation, the boundary conditions were adjusted according to the developed algorithm. Pearson correlation and Bland-Altman analyses were used to quantify the correlation and agreement between CFD calculations and transcranial Doppler (TCD) assessment.

RESULTS

A strong correlation was found between the CFD-based and invasive distal pressure measurements (P<0.0001). Meanwhile, the CFD and TCD-based flow measurements were highly correlated (r = 0.853; P = 0.001). Furthermore, there was a correlation between the mean velocity measured by CFD and the mean velocity measured by TCD (r = 0.777; P<0.001). Good agreement was observed between the mass flow by CFD simulation and volumetric flow by TCD (P = 0.0266, mean difference: -0.7814 mmHg, limits of agreement, -4.0905 - 2.5276). However, the mean velocities from CFD simulation were in less agreement with those from the TCD assessment (P = 0.3992, mean difference, -0.0485; limits of agreement, -0.6141 - 0.5170). Results of the CFD simulation indicate that the flow resistance varies greatly between individuals.

CONCLUSIONS

The computational strategy of incorporating patient-specific pressure-wire measurements may serve as an effective approach to evaluate the actual reference values of microcirculatory resistance. In addition, an individualized assessment of non-invasive flow resistance is necessary for the accurate determination of non-invasive cerebrovascular pressure.

Non-association of stroke risk with intracranial hemodynamic steal in patients with symptomatic internal carotid artery occlusions

OBJECTIVES

Paradoxical intracranial hemodynamic steal (IHS) is known in patients having persistent proximal arterial occlusions and is linked with early neurological worsening. However, stroke risk specific to symptomatic internal carotid artery occlusions (SICAO) having paradoxical IHS is unknown. Therefore, we aimed to investigate the association of paradoxical IHS in SICAO patients with stroke recurrence during a one-year follow-up.

MATERIALS AND METHODS

We prospectively enrolled adult patients having SICAO with a recent history of ischemic events. Steal magnitude (SM) to classify patients in IHS and non-IHS categories was evaluated by a breath-holding test using bilateral transcranial doppler (TCD). Patients were prescribed optimal medical therapy and followed up for one year for any ischemic stroke/TIA/cardiovascular death.

RESULTS

36 SICAO patients, mean age of 56 years, were assessed using TCD at median 22.5 days (Interquartile range, IQR= 9-42), and 11 (30.6%) had paradoxical IHS with median SM 12% (IQR= 6%-18%). On follow-up, 7 (19.4%) patients had event recurrence and its association with IHS was non-significant (IHS vs non-IHS, 18.2% vs 20%; Log-rank statistics=0.006; P=0.940). On Cox regression analysis, event recurrence was independently associated with the presence of significant contralateral stenosis only (regression coefficient= 2.237; P= 0.012; 95% CI= 1.63-53.89).

CONCLUSIONS

IHS prevalence among SICAO is high. However, paradoxical IHS was not associated with an increased risk of stroke in SICAO. Therefore, the presence of paradoxical IHS in SICAO may be considered a transit state and does not necessarily imply an increased risk of stroke.

Characterization of Cerebral Hemodynamics with TCD in Patients Undergoing VA-ECMO and VV-ECMO: a Prospective Observational Study

BACKGROUND

Extracorporeal membrane oxygenation has a high risk of acute brain injury and resultant mortality. Transcranial Doppler characterizes cerebral hemodynamics in real time, but limited data exist on its interpretation in ECMO. Here, we report TCD mean flow velocity and pulsatility index in a large ECMO population.

METHODS

This was a prospective cohort study at a tertiary care center. The patients were adults on venoarterial ECMO or venovenous ECMO undergoing TCD studies.

RESULTS

A total of 135 patients underwent a total of 237 TCD studies while on VA-ECMO (n = 95, 70.3%) or VV-ECMO (n = 40, 29.6%). MFVs were captured reliably (approximately 90%) and were similar to a published healthy cohort in all vessels except the internal carotid artery. Presence of a recordable PI was strongly associated with ECMO mode (57% in VA vs. 95% in VV, p < 0.001). Absence of TCD pulsatility was associated with intraparenchymal hemorrhage (14.7 vs. 1.6%, p = 0.03) in VA-ECMO patients.

CONCLUSIONS

Transcranial Doppler analysis in a single-center cohort of VA-ECMO and VV-ECMO patients demonstrates similar MFVs and PIs. Absence of PIs was associated with a higher frequency of intraparenchymal hemorrhage and a composite bleeding event. However, cautious interpretation and external validation is necessary for these findings with a multicenter study with a larger sample size.

Intracranial and Extracranial Evaluation

The vascular lab is an essential tool in diagnosing intracranial and extracranial disease including vasospasm from subarachnoid hemorrhage and carotid artery stenosis in the setting of stroke or transient ischemic attack. This article discusses the indications, protocol, and diagnostic criteria for transcranial doppler (TCD) and carotid artery duplex ultrasound. Intracranial and extracranial arterial testing by way of TCD and carotid imaging carries enormous implications and can provide life or death information. The learning curve for these techniques is steep but can be mastered with repetition and precise technique.

Stroke in sickle cell disease and the promise of recent disease modifying agents

Sickle cell disease (SCD) is an inherited hemoglobinopathy affecting approximately 100,000 individuals in the United States. Cerebrovascular disease is among the most common and debilitating complications of SCA, with 53% experiencing silent cerebral infarct by age 30 and 3.8% experiencing overt stroke by age 40 years. This review highlights the burden of cerebrovascular disease in SCD, including both stroke and silent cerebral infarct (SCI). We then discuss the pathophysiology of stroke and cerebral fat embolism in the absence of a patent foramen ovale. This review also reveals that options for primary and secondary stroke prevention in SCD are still limited to hydroxyurea and blood transfusion, and that the role of aspirin and anticoagulation in SCD stroke has not been adequately studied. Limited data suggest that the novel disease-modifying agents for SCD management may improve renal dysfunction, leg ulcers, and lower the abnormally high TCD flow velocity. Further research is urgently needed to investigate their role in stroke prevention in SCD, as these novel agents target the main stroke contributors in SCD - hemolysis and vaso-occlusion. This literature review also explores the role of healthcare disparities in slowing progress in SCD management and research in the United States, highlighting the need for more investment in patient and clinician education, SCD management, and research.

Vasovagal syncope with mild versus moderate autonomic dysfunction: a 13-year single-center experience

BACKGROUND

An adequate large-scale pediatric cohort based on nationwide administrative data is lacking in Korea.

PURPOSE

This study aimed to differentiate patients with VVS by autonomic dysfunction severity using the composite autonomic severity score (CASS) and compare the clinical manifestations and prognosis between patient subgroups.

METHODS

We retrospectively reviewed the medical records of 66 VVS patients divided into 3 groups by CASS. To compare the differences between these groups, we analyzed VVS type, triggers, prodromal symptoms, management of syncope, and prognosis between patients with mild versus moderate autonomic dysfunction.

RESULTS

Of our 66 patients with VVS, 41 had mild autonomic dysfunction (62.1%) and 25 had moderate autonomic dysfunction (37.9%). We found no significant intergroup differences in age, sex, inducible factor (P=0.172), prodromal symptoms, laboratory findings, head-up tilt test, type of syncope, or prognosis (P=0.154).

CONCLUSION

We found no evidence that autonomic dysfunction degree is affected by VVS characteristics, test findings, parameters, or prognosis; therefore, no further evaluations are needed to classify autonomic dysfunction severity.

Transcranial Doppler 6 h after Successful Reperfusion as a Predictor of Infarct Volume

OBJECTIVES

The aim of the study is to analyze the hemodynamic changes in the middle cerebral artery (MCA) after endovascular revascularization in acute ischemic stroke (AIS) due to large vessel occlusion and its association with the infarct volume size in the control head CT.

MATERIALS AND METHODS

Prospective study of patients with AIS due to internal carotid artery terminus or M1 segment of the MCA occlusion, who underwent endovascular treatment with a final TICI 2b-3 score, without concomitant stenosis ≥50% in both cervical carotid arteries. Transcranial Doppler ultrasound (TCD) of both MCAs was carried out at 6 h after the endovascular procedure. Mean flow velocities (MFV) after arterial reperfusion and its association with the infarct volume size in 24-36 h control head CT were determined.

RESULTS

91 patients (51 women) were included with a median age of 78 years and National institute of Health Stroke Scale of 18. The MCA was occluded in 76.92%, and intravenous thrombolysis was administered in 40.7%. The incidence of symptomatic intracranial hemorrhage was 5.5%. At three months, mortality was 19.8% and a 52.7% of patients achieved functional independence (modified Rankin Scale 0-2). After a multivariable logistic regression analysis, an increase in the MFV greater than 50% at 6 h in the treated MCA compared to contralateral MCA, was an independent predictor of large infarct volume in the control head CT with an OR 9.615 (95%CI: 1.908-47.620), p=0.006 CONCLUSIONS: Increased MFV assessed by TCD examination following endovascular recanalization is independently associated with larger infarct volume.

Cerebral Perfusion and Brain Oxygen Saturation Monitoring with: Jugular Venous Oxygen Saturation, Cerebral Oximetry, and Transcranial Doppler Ultrasonography

Accumulating evidence indicates that cerebral desaturation in the perioperative period occurs more frequently than recognized. Combining monitoring modalities that reflect different aspects of cerebral perfusion status, such as near-infrared spectroscopy, jugular bulb saturation, and transcranial Doppler ultrasonography, may provide an extended window for prevention, early detection, and prompt intervention in ongoing hypoxic/ischemic neuronal injury and, thereby, improve neurologic outcome. Such an approach would minimize the impact of limitations of each monitoring modality, while individual components complement each other, enhancing the accuracy of acquired information. Current literature has failed to demonstrate any clear-cut clinical benefit of these modalities on outcome prognosis.

Extended neuromonitoring in aortic arch surgery : A case series

BACKGROUND

Aortic arch repair for aortic dissection is still associated with a high mortality rate. Providing adequate means of neuromonitoring to guide cerebral hemodynamics is advantageous, especially during selective anterior cerebral perfusion (SACP).

OBJECTIVE

We aimed to investigate an easy multimodal neuromonitoring set-up consisting of processed electroencephalography (EEG), near infrared spectroscopy (NIRS), and transcranial doppler sonography (TCD).

MATERIAL AND METHODS

We collected intraoperative data from six patients undergoing surgery for aortic dissection. In addition to standard hemodynamic monitoring, patients underwent continuous bilateral NIRS, processed EEG with bispectral index (BIS), and intermittent transcranial doppler sonography of the medial cerebral artery (MCA) with a standard B‑mode ultrasound device. Doppler measurements were taken bilaterally before cardiopulmonary bypass (CPB), during CPB, and during SACP at regular intervals.

RESULTS

Of the patients four survived without neurological deficits while two suffered fatal outcomes. Of the survivors two suffered from transient postoperative delirium. Multimodal monitoring led to a change in CPB flow or cannula repositioning in three patients. Left-sided mean flow velocities of the MCA decreased during SACP, as did BIS values.

CONCLUSION

Monitoring consisting of BIS, NIRS, and TCD may have an impact on hemodynamic management in aortic arch operations.

Remote Ischemic Pre-conditioning in Subarachnoid Hemorrhage: A Prospective Pilot Trial

BACKGROUND

Cerebral injury from aneurysmal subarachnoid hemorrhage (aSAH) is twofold. The initial hemorrhage causes much of the injury; secondary injury can occur from delayed cerebral ischemia (DCI). Remote ischemic preconditioning (RIPC) is a mechanism of organ protection in response to transient ischemia within a distant organ. This pilot trial sought to apply RIPC in patients with aSAH to evaluate its effect on secondary cerebral injury and resultant outcomes.

METHODS

Patients were randomized to the high-pressure occlusion group (HPO) or the low-pressure occlusion group (LPO). Lower extremity RIPC treatment was initiated within 72 h of symptom onset and every other day for 14 days or until Intensive Care Unit (ICU) discharge. In HPO, each treatment consisted of 4 five-minute cycles of manual blood pressure cuff inflation with loss of distal pulses. LPO received cuff inflation with lower pressures while preserving distal pulses. Retrospectively matched controls were also analyzed. Efficacy of treatment was measured by total days spent in vasospasm out of study enrollment days, hospital and ICU length of stay (LOS), cerebral infarction, one and six month modified Rankin score, and mortality.

RESULTS

The final analysis included 33 patients with 11 in each group. Patient demographics, aneurysm location, admission airway status, Glasgow Coma Scale (GCS), modified Rankin score, Hunt and Hess score, modified Fisher Score and aneurysm management were not significantly different between groups. Hospital and ICU LOS was shorter in LPO compared to the control (p = 0·0468 and p = 0·0409, respectively). Total vasospasm days/study enrollment days, cerebral infarction, one and six month modified Rankin score, and mortality were not significantly different between the groups.

CONCLUSIONS

This pilot trial did demonstrate feasibility and safety. The shortened LOS in the LPO may implicate a protective role of RIPC and warrants future study.

Surface Point Cloud Ultrasound with Transcranial Doppler: Coregistration of Surface Point Cloud Ultrasound with Magnetic Resonance Angiography for Improved Reproducibility, Visualization, and Navigation in Transcranial Doppler Ultrasound

Transcranial Doppler (TCD) ultrasound is a standard tool used in the setting of recent sub-arachnoid hemorrhage (SAH). By tracking velocity in the circle-of-Willis vessels, vasospasm can be detected as interval velocity increase. For this disease process, repeated TCD velocity measurements over many days is the basis for its usefulness. However, a key limitation to TCD is its user dependence, which is itself largely due to the fact that exact information about probe positioning is lost between subsequent scans. Surface point cloud ultrasound (SPC-US) was recently introduced as a general approach combining ultrasound and three-dimensional surface imaging of patient + probe. In the present proof-of-principle demonstration, we have applied SPC-US to TCD and co-registered the skin surface with that from MRA images to provide a roadmap of the vasculature in 3D space for better speed, accuracy, reproducibility, and potential semi-automation of TCD. Collating the acronyms, we call the combined approach SPC-US-TCD. TCD of the M1 was obtained while three-dimensional photographic images were obtained with the Structure Sensor camera. MRA imaging was also obtained. SPC-US-TCD and corresponding MRA 3D reconstruction images were co-registered in MeshMixer using the skin surfaces for alignment. A cylinder the width of the TCD probe was placed over the fused images and aligned with the direction and orientation of the TCD probe to demonstrate the acoustic beam. In the fused images, the acoustic beam intersects the right M1 segment of the middle cerebral artery (MCA). The angle of insonation is well demonstrated and measurable in various planes. Distance measurements made in Blender localized the TCD probe position based on three skin surface landmarks, and tabulated orientation based on three angles along the corresponding directions. SPC-US-TCD provides valuable information that is otherwise not present in TCD studies. By co-registering SPC-US-TCD data with that from cross sectional vessel imaging, precise probe location relative to external skin surface landmarks as well as 3D vessel location relative to TCD probe placement offers the potential to provide a roadmap that improves exam reproducibility, speed of acquisition, and accuracy. The goal of future work is to demonstrate this improvement statistically by application to multiple patients and scans.

What is the place of hematopoietic stem cell transplantation in the management of cerebral vasculopathy in children with sickle cell anemia?

Cerebral vasculopathy is the most severe complication affecting children with sickle cell anemia. Significant progress has been made in the management of sickle cell anemia cerebral vasculopathy, including early transcranial Doppler screening, chronic transfusion, andhydroxyurea. Nevertheless, for patients with a potential matched-sibling donor (MSD), stem cell transplantation (SCT) is now the treatment offering the best cerebral vasculopathy outcome. In the absence of MSD,alternative SCT should be recommended only in those with worsening cerebral vasculopathy despite standard treatments, and should be limited to related haplo-identical SCT undertaken in controlled studies.

A Novel Nonlinear System Identification for Cerebral Autoregulation in Human: Computer Simulation and Validation

Cerebral autoregulation in healthy humans was studied using a novel methodology adapted from Bendat nonlinear analysis technique. A computer simulation of a high-pass filter in parallel with a cubic nonlinearity followed by a low-pass filter was analyzed. A linear system transfer function analysis showed an incorrect estimate of the gain, cut-off frequency, and phase of the high-pass filter. By contrast, using our nonlinear systems identification, yielded the correct gain, cut-off frequency, and phase of the linear system, and accurately quantified the nonlinear system and following low-pass filter. Adding the nonlinear and linear coherence function indicated a complete description of the system. Cerebral blood flow velocity and arterial pressure were measured in six data sets. Application of the linear and nonlinear systems identification techniques to the data showed a high-pass filter, like the linear transfer function, but the gain was smaller. The phase was similar between the two techniques. The linear coherence was low for frequencies below 0.1 Hz but improved by including a nonlinear term. The linear + nonlinear coherence was approximately 0.9 across the frequency bandwidth, indicating an improved description over the linear system analysis of the cerebral autoregulation system.

Burden of neurological and neurocognitive impairment in pediatric sickle cell anemia in Uganda (BRAIN SAFE): a cross-sectional study

Background

Children with sickle cell anemia (SCA) are highly susceptible to stroke and other manifestations of pediatric cerebral vasculopathy. Detailed evaluations in sub-Saharan Africa are limited.

Methods

We aimed to establish the frequency and types of pediatric brain injury in a cross-sectional study at a large SCA clinic in Kampala, Uganda in a randomly selected sample of 265 patients with HbSS ages 1–12 years. Brain injury was defined as one or more abnormality on standardized testing: neurocognitive impairment using an age-appropriate test battery, prior stroke by examination or transcranial Doppler (TCD) velocities associated with stroke risk in children with SCA (cerebral arterial time averaged mean maximum velocity ≥ 170 cm/second).

Results

Mean age was 5.5 ± 2.9 years; 52.3% were male. Mean hemoglobin was 7.3 ± 1.01 g/dl; 76.4% had hemoglobin < 8.0 g/dl. Using established international standards, 14.7% were malnourished, and was more common in children ages 5–12. Overall, 57 (21.5%) subjects had one to three abnormal primary testing. Neurocognitive dysfunction was found in 27, while prior stroke was detected in 15 (5.7%). The most frequent abnormality was elevated TCD velocity 43 (18.1%), of which five (2.1%) were in the highest velocity range of abnormal. Only impaired neurocognitive dysfunction increased with age (OR 1.44, 95%CI 1.23–1.68), p < 0.001). In univariate models, malnutrition defined as wasting (weight-for-height ≤ −2SD), but not sex or hemoglobin, was modestly related to elevated TCD (OR 1.37, 95%CI 1.01–1.86, p = 0.04). In adjusted models, neurocognitive dysfunction was strongly related to prior stroke (OR 6.88, 95%CI 1.95–24.3, p = .003) and to abnormal TCD (OR 4.37, 95%CI 1.30, p = 0.02). In a subset of 81 subjects who were enriched for other abnormal results, magnetic resonance imaging and angiography (MRI/MRA) detected infarcts and/or arterial stenosis in 52%. Thirteen subjects (25%) with abnormal imaging had no other abnormalities detected.

Conclusions

The high frequency of neurocognitive impairment or other abnormal results describes a large burden of pediatric SCA brain disease in Uganda. Evaluation by any single modality would have underestimated the impact of SCA. Testing the impact of hydroxyurea or other available disease-modifying interventions for reducing or preventing SCA brain effects is warranted.

Relationship Between Brain Pulsatility and Cerebral Perfusion Pressure: Replicated Validation Using Different Drivers of CPP Change

Background

Determination of relationships between transcranial Doppler (TCD)-based spectral pulsatility index (sPI) and pulse amplitude (AMP) of intracranial pressure (ICP) in 2 groups of severe traumatic brain injury (TBI) patients (a) displaying plateau waves and (b) with unstable mean arterial pressure (MAP).

Methods

We retrospectively reviewed patients with severe TBI and continuous TCD monitoring displaying either plateau waves or unstable MAP from 1992 to 1998. We utilized linear and nonlinear regression techniques to describe both cohorts: cerebral perfusion pressure (CPP) versus AMP, CPP versus sPI, mean ICP versus ICP AMP, mean ICP versus sPI, and AMP versus sPI.

Results

Nonlinear regression techniques were employed to analyze the relationships with CPP. In plateau wave and unstable MAP patients, CPP versus sPI displayed an inverse nonlinear relationship (R² = 0.820 vs. R² = 0.610, respectively), with the CPP versus sPI relationship best modeled by the following function in both cases: PI = a + (b/CPP). Similarly, in both groups, CPP versus AMP displayed an inverse nonlinear relationship (R² = 0.610 vs. R² = 0.360, respectively). Positive linear correlations were displayed in both the plateau wave and unstable MAP cohorts between: ICP versus AMP, ICP versus sPI, AMP versus sPI.

Conclusions

There is an inverse relationship through nonlinear regression between CPP versus AMP and CPP versus sPI display. This provides evidence to support a previously-proposed model of TCD pulsatility index. ICP shows a positive linear correlation with AMP and sPI, which is also established between AMP and sPI.

Electronic supplementary material

The online version of this article (doi:10.1007/s12028-017-0404-9) contains supplementary material, which is available to authorized users.

Contrast-Enhanced Color-Coded Doppler Sonography in Moyamoya Disease: A Retrospective Study

The purpose of this study was to validate the feasibility of contrast-enhanced transcranial Doppler sonography (CE-TCCD) in the diagnosis of Moyamoya disease (MMD). CE-TCCD data on patients with MMD were analyzed. The CE-TCCD data were classified qualitatively into four patterns by two independent investigators: normal vascular color Doppler signal (pattern 1), augmented color Doppler signal with identifiable vascular structure (pattern 2), confluent color Doppler signal filling more than two-thirds of the display frame without identifiable vascular structure (pattern 3) and confluent color Doppler signal filling full display (pattern 4). To investigate the validity, we compared the CE-TCCD data with traditional transcranial Doppler data and Suzuki grades on cerebral angiography. A total of 32 CE-TCCD studies from 16 MMD patients (male 37.5%, median age 48) were included in this study. The CE-TCCD findings were distributed across patterns 1 (n = 3), 2 (n = 12), 3 (n = 10) and 4 (n = 7) and were correlated with the Suzuki grades (p <0.005) and hemodynamic parameters. Inter-rater reliability was promising (Cronbach α = 0.883). The CE-TCCD test provides distinctive patterns in MMD, according to their stage of progression. CE-TCCD patterns seem to be a reliable and valid means for the evaluation of MMD.

Increased pulsatility index supports diagnosis of vascular parkinsonism versus idiopathic Parkinson's disease

INTRODUCTION

The diagnosis of vascular parkinsonism (VP) is based on a series of clinical criteria and neuroimaging findings. An increase in transcranial Doppler ultrasonography pulsatility index (PI) has been described as a frequent finding in patients with VP. We aimed to confirm this association and to determine the PI value with the highest sensitivity and specificity for diagnosis of VP.

METHOD

PI was determined in all patients admitted to Hospital Universitari i Politècnic La Fe due to parkinsonism between January 2012 and June 2016. We assessed the probability of having VP based on PI values in patients with a definite diagnosis of either VP or idiopathic Parkinson's disease (IPD). A ROC curve was created to determine the PI value with the highest sensitivity and specificity.

RESULTS

We assessed a total of 146 patients with suspected parkinsonism; 54 (37%) were diagnosed with IPD and 15 (10%) with VP. Patients with VP were significantly older than those with IPD (mean age of 79 vs 68.5, P=.00144) and had a higher PI (median of 1.29 [IQR: 1.09-1.38] vs 0.96 [IQR: 0.89-1.16], P=.01328). In our sample, a PI of 1.09 conferred 84% sensitivity and 70% specificity.

CONCLUSIONS

In our series, the PI was significantly higher in patients with VP than in those with IPD. We therefore support the use of transcranial Doppler ultrasonography for the initial assessment of elderly patients with akinetic-rigid syndrome.

Cerebral Critical Closing Pressure: Is the Multiparameter Model Better Suited to Estimate Physiology of Cerebral Hemodynamics?

BACKGROUND

Cerebral critical closing pressure (CrCP) is the level of arterial blood pressure (ABP) at which small brain vessels close and blood flow stops. This value is always greater than intracranial pressure (ICP). The difference between CrCP and ICP is explained by the tone of the small cerebral vessels (wall tension). CrCP value is used in several dynamic cerebral autoregulation models. However, the different methods for calculation of CrCP show frequent negative values. These findings are viewed as a methodological limitation. We intended to evaluate CrCP in patients with severe traumatic brain injury (TBI) with a new multiparameter impedance-based model and compare it with results found earlier using a transcranial Doppler (TCD)-ABP pulse waveform-based method.

METHODS

Twelve severe TBI patients hospitalized during September 2005-May 2007. Ten men, mean age 32 years (16-61). Four had decompressive craniectomies (DC); three presented anisocoria. Patients were monitored with TCD cerebral blood flow velocity (FV), invasive ABP, and ICP. Data were acquired at 50 Hz with an in-house developed data acquisition system. We compared the earlier studied "first harmonic" method (M1) results with results from a new recently developed (M2) "multiparameter method."

RESULTS

M1: In seven patients CrCP values were negative, reaching -150 mmHg. M2: All positive values; only one lower than ICP (ICP 60 mmHg/ CrCP 57 mmHg). There was a significant difference between M1 and M2 values (M1 < M2) and between ICP and M2 (M2 > ICP).

CONCLUSION

M2 results in positive values of CrCP, higher than ICP, and are physiologically interpretable.

Relationship of retinal vascular caliber variation with intracranial arterial stenosis

BACKGROUND & PURPOSE

To investigate the associations of retinal vessel parameters with intracranial arterial stenosis (ICAS) assessed by Transcranial Doppler ultrasonography.

METHOD

Data on transcranial Doppler ultrasonography and quantitative retinal vessel parameters from 627 participants in a health screening program were included in this study. ICAS was defined as >50% intracranial arterial stenosis (ICAS) based on criteria modified from the stroke outcomes and neuroimaging of intracranial atherosclerosis (SONIA) trial assessed by transcranial Doppler (TCD) ultrasonography. A semi-automated computer-assisted program (Singapore I Vessel Assessment) was used to measure the retinal vascular parameters from the photographs. Multivariate analysis was performed to identify which retinal vessel parameters were associated with increased risk of ICAS.

RESULTS

Among 627 participants, 24 (3.8%) had ICAS diagnosed by TCD. Subjects with ICAS had eyes with wider mean central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) in comparison to subjects without ICAS. Men (odds ratio [OR]:13.1, 95% confidence interval: 3.13-33.33) and a large standard deviation of mean arterial width (STDWa) were associated with ICAS (first vs. third tertile: OR ratio: 14.04, 95% confidence interval: 1.71-115.32; first vs. third tertile: OR ratio: 22.1, 95% confidence interval: 2.56-190.97) after adjusting for possible confounders.

CONCLUSION

A large variation in retinal arteriolar diameter is associated with ICAS. This study suggests the possible relationship between retina vessel and early changes within the cerebrovascular network.

The acute effects of alcohol on cerebral hemodynamic changes induced by the head-up tilt test in healthy subjects

BACKGROUND

Alcohol is a known triggering factor for orthostatic dysfunction, increasing the risk of neurally-mediated syncope. Since orthostatic tolerance may be affected by both systemic and cerebral hemodynamic changes, our aim was to investigate the acute effects of alcohol on cerebral vasoreactivity measured during the head-up tilt (HUT) test in 20 healthy subjects.

METHODS

Mean arterial blood pressure (mBP), heart rate, and flow parameters in both middle cerebral arteries (MCAs) were continuously recorded in the supine and during a 10-minute HUT positions before and after alcohol intake.

RESULTS

The HUT test resulted in a more prominent decline of adjusted mBP at the level of MCAs (mBPMCA) and a significantly larger decrease of MCA mean flow velocities (MFVMCA) in the post-alcohol period than before alcohol intake. During the HUT phase, the relative decrease in MFVMCA was significantly smaller than the reduction in mBPMCA before drinking alcohol, while these changes were similar after alcohol ingestion. The cerebrovascular resistance index (CVRi) decreased during the HUT phase in the control period, however, it increased after alcohol intake.

CONCLUSION

The similar decrease in mBPMCA and MFVMCA during orthostatic stress after alcohol ingestion together with the increased CVRi indicated the impairment of the compensatory vasodilation of cerebral resistance vessels, i.e. impaired cerebral autoregulation. These findings suggest that alcohol may contribute to impaired orthostatic tolerance not only by a hypotensive response but also by the alteration of cerebral blood flow regulation.

The curative effect comparison of two kinds of therapeutic regimens on decreasing the relative intensity of microembolic signal in CLAIR trial

BACKGROUND

Microembolic signals (MESs) are direct markers of unstable large artery atherosclerotic plaques. In a previous study, we found that the number of MESs is associated with stroke recurrence and that clopidogrel plus aspirin more effectively reduce the number of MESs than does aspirin alone. Stroke recurrence is associated with not only the number of MESs but also the size of the MES, which can theoretically be estimated by monitoring the MES intensity via transcranial doppler (TCD). Thus, we compared the effects of clopidogrel and aspirin with aspirin alone on MES intensity using TCD.

METHODS

We recruited 100 patients who experienced acute ischemic stroke or transient ischemic attack (TIA) within 7days of symptom onset. All patients also had large artery stenosis in the cerebral or carotid arteries and the presence of MES as revealed by TCD. The patients were randomized to receive either aspirin or clopidogrel and aspirin for 7days. MES monitoring was performed on days 2 and 7.

RESULTS

Intent-to-treat (ITT) analysis (46 patients in the dual therapy group, 52 patients in the monotherapy group) and per-protocol (PP) analysis (25 patients in the dual therapy group, 31 patients in the monotherapy group) were performed on 98 patients. The primary finding was that the MES intensity was dramatically reduced in the dual therapy group. ITT analysis of the dual therapy group revealed that the MES intensity was 8.04 (0-16) dB before treatment, 0.00 (0-17) dB on day 2, and 0.00 (0-12) dB on day 7 (P=0.000). In the monotherapy group, the MES intensity was 9.00 (0-20) dB before treatment, 8.25 (0-17) dB on day 2, and 7.0 (0-18) dB on day 7 (P=0.577). PP analysis revealed similar results. No severe hemorrhagic complications were detected. The two patients in this study who experienced stroke recurrence were in the monotherapy group.

CONCLUSIONS

Clopidogrel and aspirin more effectively decrease the MES intensity than aspirin alone in patients with large artery stenotic minor stroke or TIA.

Protocol Based Real-Time Continuous Electroencephalography for Detecting Vasospasm in Subarachnoid Hemorrhage

A continuous electroencephalography (cEEG) can be helpful in detecting vasospasm and delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage (SAH). We describe a patient with an aneurysmal SAH whose symptomatic vasospasm was detected promptly by using a real-time cEEG. Patient was immediately treated by intraarterial vasodilator therapy. A 50-year-old woman without any significant medical history presented with a severe bifrontal headache due to acute SAH with a ruptured aneurysm on the anterior communicating artery (Fisher grade 3). On bleed day 6, she developed a sudden onset of global aphasia and left hemiparesis preceded by cEEG changes consistent with vasospasm. A stat chemical dilator therapy was performed and she recovered without significant neurological deficits. A real-time and protocol-based cEEG can be utilized in order to avoid any delay in detection of vasospasm in aneurysmal SAH and thereby improve clinical outcomes.

Cerebral vasculitis as a major manifestation of rheumatoid arthritis

OBJECTIVE AND IMPORTANCE

Cerebral vasculitis (CV) is a rare described complication of rheumatoid arthritis (RA). Although the most frequent neurological manifestations of RA are peripheral neuropathy and cervical spinal cord compression due to subluxation of the cervical vertebrae, CV can be seen especially in patients with seropositive and long-standing RA.

CLINICAL PRESENTATION

We report two cases of CV associated with RA. Both patients had no extraarticular manifestations and RA clinics were under control. Our first case is a 30-years-old woman with seropositive RA for 15 years who had suddenly onset left facial and upper extremity weakness. In magnetic resonance imaging (MRI) DWI, hyperintensity in frontotemporal region due to acute ischaemia was detected. The new lacuner acute ischaemic lesions in right precentral gyrus, bilateral frontoparietal and corpus callosal region were detected in the control MRI. The cerebral MR angiography and transcranial doppler findings were consistent with CV. The patient responded favourably to pulse methylprednisolone and oral azathiopurine treatments. The second patient is a 52-year-old man who had been RA for 29 years. He admitted to our neurology clinic with speech difficulty and right upper extremity minimal weakness. Magnetic resonance imaging DWI showed left parietooccipital acute ischaemia which was progressed within a week and a new right parietooccipital ischaemia was added. His cerebral MR angiography and cerebral angiography were concordant with CV. The cyclophosphamide therapy was started since the cerebral ischaemia was progressed during pulse methylprednisolone and he responded well to this therapy.

CONCLUSION

CV due to RA is an uncommon serious complication which can be life-threatening. Therefore clinicians should be aware of the possibility of CV especially in progressive strokes in RA.

Selective head cooling for the treatment of neurologic complications of acute liver failure in a newborn with disseminated herpes infection

Background

Neurologic complications of pediatric acute liver failure (ALF) are a major determinant of outcome. Management of these complications, including increased intracranial pressure (ICP) is largely supportive. Although hypothermia is an effective treatment for perinatal asphyxia and is used to reduce ICP following traumatic brain injury, it has not been evaluated for neurologic complications of ALF in the newborn.

Methods

Case report.

Results

We present a case of neonatal herpes simplex virus (HSV)-associated ALF with profound neurologic impairment and increased ICP. The patient was treated with selective head cooling, and monitored with transcranial doppler (TCD) studies of cerebral blood flow velocity, and electroencephalograms (EEG). The duration of head cooling was influenced by absent diastolic flow on TCDs, which subsequently improved during hypothermia. Continuous EEGs captured subclinical seizures, which improved with antiepileptic medications. Her death was attributed to a massive pulmonary hemorrhage and a hypoxemic cardiac arrest secondary to significant coagulopathy.

Conclusion

This case demonstrates that selective head cooling may attenuate increased ICP in neonatal encephalopathy, and that TCDs may guide management in the absence of invasive monitoring.

Transcranial Doppler with bubble study as a method to detect extracardiac right-to-left shunts in patients with ischemic stroke

BACKGROUND AND PURPOSE

Paradoxical embolism through extracardiac right-to-left shunts (ECRLS) may represent an under-detected stroke mechanism. Stroke patients without evidence of cardiac right-to-left shunt (RLS) on echocardiogram may benefit from transcranial Doppler with bubble study (TCD-b) to aid in recognition of stroke etiology. This study assesses the usefulness of TCD-b in the stroke evaluation.

METHODS

Retrospective cohort study of consecutive patients undergoing TCD-b performed in our neurovascular laboratory from February 2005 to August 2009. Echocardiography results were reviewed in patients with positive TCD-b. Detailed medical record review was performed on patients with positive TCD-b and negative echocardiogram findings for RLS.

RESULTS

Of 502 patients undergoing TCD-b, 48.4% (n = 243) had a positive study suggesting the presence of RLS. Of these, 59.2% (n = 144) had an echocardiogram demonstrating a cardiac RLS, 26% (n = 63) had echocardiograms without evidence of cardiac RLS, and 14.8% (n = 36) had no echocardiogram. Data on the evaluation to determine source of potential shunting in patients with discrepant findings was available in 11(17.5%). Of these, 63.6% (7/11) had potential mechanisms for positive TCD-b: one pulmonary arteriovenous malformation (AVM), one arteriovenous fistula thrombus, one parietal AVM, and four had malignancy.

CONCLUSIONS

TCD-bubble studies may prove useful in uncovering treatable causes of stroke.